1. Field of Technology
The present invention relates to a label peeling mechanism for peeling labels from a web liner to which the labels are adhesively affixed by conveying the label paper with the web curving acutely back to itself from the non-label side of the web liner. The invention also relates to a label printer having a label peeling mechanism for peeling labels from the web liner after the labels are printed.
2. Description of the Related Art
Label printers for printing and issuing labels typically print to rolled label paper composed of a web liner having adhesive labels of a constant length peelably affixed to one side (referred to herein as the “front”) of the web. This label printer conveys the label paper until a label reaches the printing position where the label is printed by the printing mechanism. The label paper is then conveyed downstream to the label peeling mechanism whereby the printed labels are removed from the web, and the peeled labels and the web liner are then discharged from separate discharge paths. A typical label peeling mechanism conveys the web with the labels affixed thereto through a path that curves the web from the back side (non-label side) thereof through an angle of less than or equal to 90 degrees and uses the stiffness of the labels (out-of-plane stiffness) to gradually disengage the labels from the liner starting from the leading edge of each label. A printer having this type of label peeling mechanism is taught in Japanese Unexamined Patent Appl. Pub. H4-272876, for example.
This type of label peeling mechanism has a web guide disposed to curve and guide the back side of the web liner around a corner of 90 degrees or less, and conveys the web liner in contact with this web guide. The smaller the radius of curvature through which the web liner is conveyed, the more reliably the labels can be peeled from the liner.
When the label paper is provided in a roll, a continuous web liner having labels affixed on the surface thereof at a constant interval is wound onto a roll. The labels are affixed with adhesive to the surface of the web, and adhesive is left on the surface of the web even after the labels are peeled from the web. A small amount of adhesive is also present around the area of the labels affixed to the web. This results in the transfer of adhesive to the parts of the transportation path that contact the web and the label surfaces. As adhesive thus accumulates on the transportation path, the web and labels tend to stick to these parts of the transportation path that are now sticky. This makes it difficult to transport the web accurately for label positioning, for example, and also leads to paper jams and other problems.